Metal can and closure therefor



June 7, 1932. A. G. HOPKINS METAL CAN AND CLOSURE THEREFOR Filed Nov.25, 1930 Patented June 7, 1932 UNITED STATES PATENT caries ARTHUR G.HOPKINS, OF MASPETH,

PORATION, OF NEW YORK, N. Y.

METAL CAN AND CLOSURE THEREFOR Application filed November 25, 1930.

This invention relates to metal cans and to closures therefor, and moreparticularly to such cans and closures intended to form an air-tightmetal container.

Metal cans are ordinarily provided with an opening through which the canmay be filled or emptied, and with a plug or closure adapted to beforced into the opening. When the cans are first filled at the factory,it is customary to apply the closure by striking the same with a mallet.This frequently forces the closure into the can opening at a slant, dueeither to the closure having been initially positioned out of level, ordue to its being struck at an angle. This results in a line contact,instead of a surface contact, which reduces the efi'ectiveness of theseal between the can and its cover, and, furthermore, mutilates ordeforms the can opening, which prevents the obtaining of the desiredtight sealing fit.

Even if the insert or closure has been initially hammered into placecorrectly, the can opening is apt to be deformed out of round when thecan is opened, particularly if the screw driver or similar implementused to open the can is worked mostly at one side of the cover. This,again, will prevent accurate fit between the closure and can when thecan is re-sealed.

And if the can is first sealed properly, and then opened carefully andevenly all around the periphery of the closure, the can opening may yetbe deformed when the can is resealed, by forcing the closure into thecan opening at a slant. The condition, may, of course, be aggravated bythe occurrence of two or more of the above factors, for the can openingor/and cover may be deformed in any one direction at one time, andthereafter be deformed in another direction at another time, so that aline contact, rather than a surface contact, is at best obtainable, andin extreme cases there may be no contact at all at a portion of theperiphery of the can opening. 7

With the general object in View, of obviating all of the foregoingdifliculties and of facilitating the closing, opening, and re-sealing ofthe can, I have heretofore devised a Serial No. 498,006.

novel closure for such a can, the side wall of which is stepped so as toform a straight centering portion which is dimensioned to readily fitthe can opening, a transition portion, and a straight sealing portionwhich is dimensioned for a force or friction fit with the can opening.This prior invention is disclosed in detail in my copending applicationSer. N 0. 490,111 filed October 21, 1930.

The object of the present invention, generally speaking, is to improvethe metal can disclosed in my aforesaid copending application. Morespecifically, it is an object of the present invention to so combine thecan and closure that the desired accurate force or friction fit betweenthe can and closure will exist near the bottom of the closure, at whichpoint it is relatively rigid and certain to retain its shape. Anotherobject is to obtain the desired force or friction contact near thebottomof the depending flange of the can opening, at which point theflange is most resilient and capable of a snug fit even after the canhas been opened and closed a considerable number of times. A stillfurther object of the present invention is to so relate the can andclosure that the closure may be of standard or conventional type, makingit readily interchangeable with the closures of other cans of similardimension, and readily replaceable if lost.

To accomplish the foregoing objects, I provide the can with a cover seathaving a downwardly depending flange defining a can opening, but thesaid flange instead of being straight, is provided with a straightcentering portion dimensioned to readily fit the closure, a preferablytapered transition portion, and a straight sealing portion which isdimensioned for a force or friction fit with the closure. The latter maythen be provided with a straight side wall, and in all respects may beof perfectly conventional type. With this construction, all of theadvantages of my prior construction are retained, andv at the same timeadditional advantages are obtained because any deformation of theclosure due to opening the same with a screw driver or the like, takesplace at the upper part, rather than the lower part thereof. The lowerportion of the closure is rigid and holds its shape accurately, and asnug fit therewith by the can opening is insured, because the dependingflange wall of the latter is mostly resilient at the lowermost portionthereof.

To the accomplishment of the foregoing and such other objects as willhereinafter appear, my invention consists in the metal can elements andtheir relation one to the other as hereinafter are more particularlydescribed in the specification and sought tov be defined in the claims.The specification is accompanied by a drawing in which:

Fig. 1 is an elevation taken in section through a metal can embodyingthe features of my invention;

Fig. 2 is a section through the upper por tion of the can, showing theclosure in place preparatory to being forced home; and

Fig. 3 is a section similar to Fig. 2, but showing the closure forcedhome.

Referring to the drawing, the body of the metal can may be ofconventional type, comprising a side wall 12, and abottom. wall 14 whichis applied thereto and sealed in any desired manner, as by soldering theseam 16. The can further comprises a cover seat 18 applied to theopposite end of the side wall 12, and also sealed thereto in any desiredmanner, as by soldering the joint 20.

The cover seat 18 is provided with a downwardly extending or dependingflange which defines the can opening, but this flange instead of beingstraight, is designed to fit and cooperate with the can plug or closure22 in a novel manner. The closure 22 may be of conventional type,including the usual annular flange 2a and depressed central portion 26joined by a straight side wall 28.

The depending flange of the cover seat 18 is stepped into a plurality ofportions of dif ferent dimension, and more particularly, is providedwith a straight centering portion 30 which is dimensioned to readily fitor freely receive the closure 22, and a straight sealing portion 32which is dimensioned for a force or friction fit with the closure 22,and these straight portions are preferably joined by a transitionportion 34 which may be tapered in the manner shown. The lower edge ofthe straight portion 32 may be rolled to form a head 36 whichstrengthens and increases the resilience of the straight portion 32 ofthe flange. It may be mentioned that the stepping or change in diameterof the side wall of the closure indicated in the drawing, is somewhatexaggerated for the sake of clarity, and that in actual practice thedifference in dimension is rather slight, the centering portion 30 beingdesigned to receive the closure accurately although without a frictionor force fit, while the sealing portion is smaller by only that slightamount needed to obtain the desired friction or force fit.

In operation the filled cans may be capped accurately in a facile andrapid manner, because the closure 22 may be preliminarily seated in thecan opening without resistance, and rests upon the transition portion 34in the manner shown in Fig. 2. In this position the closure centersitself and assumes the desired horizontal position. When the cover isforced home in the manner shown in Fig. 3, it remains in true alignmentwith the can opening, first, because it is initially seated properly,second, because it is guided by the centering portion 30 of the canopenin and, third, because the additional distance which it must bedriven is only a fraction of the total ieight of the side wall of theclosure.

While the invention is applicable to metal cans intended for any use, it1s particularly useful in connection with cans carrying paints or otherliqulds or sollds necessltating a perfectly air-tight closure. In thecase of such cans, it is essential to avoid deformation of the closureor/and can opening when first closing the can, and also when opening orclosing the can at subsequent times. With the present can deformation isavoided when closing the can, because of the factors outlined in thepreceding paragraph. Deformation is further avoided when opening the canbecause even if the closure is pried open entirely at one side thereof,no appreciable mutilation takes place because the closure, afterreaching only a slight tilt, comes to the enlarged or centering portion30 of the can opening, at which point the closure is freed from the can.

The accuracy of the mating walls of the can and closure is furtherpreserved, because the friction walls are located at the bottom of theclosure and can opening. It will be evident that the side wall 28 of theclosure is most rigid and most capable of retaining its original shapeat the lower portion thereof, where it is stayed by the bottom wall 26.Furthermore, in prying theclosure open with a screw driver or similartool, the upper portion of the side wall 28 may be deformed, but thisdeformation does not reach down to the lower portion of the side wall28. With respect to the depending flange wall of the cover seat 18, itwill be readily understood that the lower portion thereof is quiteresilient relative to the upper portion thereof, and in the presentstructure this portion is the effective sealing portion. The resiliencyof the sealing portion 32 insures a snug fit with the closure, evenafter the can has been opened and closed a considerable number of times.It may also be observed that locating the sealing portion of the can atthe bottom of the closure is particularly convenient when deal-- ingwith liquids such as paint. because the paint is kept in contact withonly the bottom of the closure, which avoids that inconvenience andsloppiness which result when the side wall of the closure is coated withpaint.

Another advantage of the present form of my invention resides in thefact that the closure 22 may be of perfectly conventional type andtherefore is interchangeable with other closures of like size, and iflost may be readily replaced.

When the can is intended to be used as an air-tight package, the canopening and closure are preferably, though not necessarily, madecircular, so that the side wall 28 of the closure is cylindrical, aswell as the centering and sealing portions 30 and 32 of the can opening,while the transition portion 34: may be appropriately rounded, tapered,or conical.

The use of the stepped straight portions employed in my invention shouldnot be confused with the use of a tapered wall, because a tapered wallwill result in only a line contact, rather than a surface contact; atapered wall will not insure horizontal seating of the closure, and isvery apt to cause the latter to be seated and subsequently driven homeat a slant; and a particularly poor fit is apt to result when the can isclosed several times, because in each case the cover may be forced homeat a different slant.

It is thought that the manner of constructing and using my invention,and the many advantages thereof, will be apparent from the foregoingdetailed description thereof. It will be apparent that while I haveshown and described my invention in the preferred form, many changes andmodifications may be made in the structure disclosed, without departingfrom the spirit of the invention, defined in the following claims.

I claim:

1. A can comprising a flange defining a can opening for cooperation witha straightwalled plug or closure, said flange having at its upper end astraight centering portion of large dimension to readily receive saidclosure, and having at its lower end a straight sealing portion of smalldimension for receiving said closure with a force or friction fit, andhaving a transition portion interconnecting the upper and lowerportions.

2. A can comprising a cover seat including a downwardly depending flangedefining a can opening for cooperation with a plug or closure, saidflange having a straight centering portion dimensioned to readily fitsaid closure, a transition portion, and a straight sealing friction fitwith said closure.

3. A can comprising a cover seat including a downwardly depending flangedefining a circular can opening for cooperation with a cylindrical plugor closure, said flange having a cylindrical centering portiondimensioned to readily fit said closure, a transition portion, and acylindrical sealing portion dimensioned for a force or friction fit withsaid closure.

portion dimensioned for a force or 4. An air-tight metal packagecomprising a can including a flange defining the can opening, and aninternal plug or closure therefor including a straight side wall, saidflange having at its upper end a straight centering portion dimensionedto readily fit the side wall of the closure, and having at its lower enda straight sealing portion dimensioned for a force or friction fit withthe side wall of the closure, and having a transition portioninterconnecting the upper and lower portions.

5. An air-tight metal package comprising a can including a cover seathaving a downwardly depending flange defining the can opening, and aclosure therefor including a flange, a depressed central portion, and astraight side wall, said downwardly depending flange having a straightcentering portion dimensioned to readily fit the side wall of theclosure, a transition portion, and a straight sealing portiondimensioned for a force or friction fit with the side wall of theclosure.

6. An air-tight metal package comprising a can including a cover seathaving a downwardly depending flange defining the can opening, and aclosure therefor including an annular flange, a depressed centralportion, and a cylindrical side wall, said downwardly depending flangehaving a cylindrical centering portion dimensioned to readily fit theside wall of the closure, 2. transition portion, and a cylindricalsealing portion dimensioned for a force or friction fit with the sidewall of the closure.

Signed at New York in the county of New York and State of New York this21st day of November A. D. 1930.

ARTHUR G. HOPKINS.

